U.S. patent application number 15/599722 was filed with the patent office on 2017-11-23 for centrifuge rotor core with partial channels.
This patent application is currently assigned to ALFA WASSERMANN, INC.. The applicant listed for this patent is ALFA WASSERMANN, INC.. Invention is credited to Blaine J. Marsh, Sandra Patricia Merino, Kurt Spiegel.
Application Number | 20170333917 15/599722 |
Document ID | / |
Family ID | 58738991 |
Filed Date | 2017-11-23 |
United States Patent
Application |
20170333917 |
Kind Code |
A1 |
Spiegel; Kurt ; et
al. |
November 23, 2017 |
CENTRIFUGE ROTOR CORE WITH PARTIAL CHANNELS
Abstract
A rotor core is provided that includes a rotor length defined
along an axis of rotation and a plurality of separation channels.
The plurality of separation channels having a channel length
extending along the axis of rotation a distance that is less than
the rotor length. A rotor assembly is also provided that includes
such a rotor core removably disposed in an outer housing.
Inventors: |
Spiegel; Kurt; (Pearl River,
NY) ; Merino; Sandra Patricia; (Weesp, NL) ;
Marsh; Blaine J.; (Brogue, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ALFA WASSERMANN, INC. |
West Caldwell |
NJ |
US |
|
|
Assignee: |
ALFA WASSERMANN, INC.
West Caldwell
NJ
|
Family ID: |
58738991 |
Appl. No.: |
15/599722 |
Filed: |
May 19, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62338563 |
May 19, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B04B 7/08 20130101; B04B
1/00 20130101; B04B 2005/0464 20130101; B04B 5/0442 20130101 |
International
Class: |
B04B 5/12 20060101
B04B005/12; B04B 1/06 20060101 B04B001/06; B04B 5/00 20060101
B04B005/00 |
Claims
1. A rotor core comprising a rotor length defined along an axis of
rotation; and a plurality of separation channels, the plurality of
separation channels having a channel length extending along the
axis of rotation a distance that is less than the rotor length.
2. The rotor core of claim 1, wherein the channel length is between
5% and 90% of the rotor length.
3. The rotor core of claim 1, wherein the plurality of separation
channels have a channel width, the rotor core comprising an aspect
ratio of the channel width to the channel length from 10:1 to
1:10.
4. The rotor core of claim 1, further comprising a first end face
and a second end face.
5. The rotor core of claim 4, wherein the plurality of separation
channels intersect with only one of the first and second end
faces.
6. The rotor core of claim 4, wherein the first and/or second end
face comprises an insert.
7. The rotor core of claim 6, wherein the insert is integral to the
first and/or second end face.
8. The rotor core of claim 6, wherein the insert is connected to,
but biased away from, the first and/or second end face.
9. The rotor core of claim 1, further comprising a flow path
defined by an axial channel, a plurality of radial channels, the
plurality of separation channels, a plurality of face channels, the
plurality of face channels being defined in the first end face and
connecting an inlet or outlet flow to the plurality of separation
channels, the plurality of separation channels connecting the
plurality of face channels to the plurality of radial channels, the
plurality of radial channels connecting the plurality of separation
channels to the axial channel, the axial channel being defined
through the axis of rotation, and the axial channel connecting the
plurality of radial channels to the second end face.
10. The rotor core of claim 9, wherein the first end face comprises
a first insert, the flow path further comprising a plurality of
insert channels, the plurality of insert channels connecting the
plurality of face channels to the inlet or outlet flow.
11. The rotor core of claim 9, wherein the plurality of separation
channels corresponds in number to the plurality of radial and face
channels.
12. The rotor core of claim 9, further comprising a port connecting
the plurality of radial channels and the plurality of separation
channels, the port having a taper such that the port is wider at an
interface with the plurality of separation channels than at the
plurality of radial channels.
13. The rotor core of claim 9, wherein the plurality of radial
channels are perpendicular to the axis of rotation.
14. The rotor core of claim 9, wherein the plurality of radial
channels are angled with respect to a normal line through the axis
of rotation.
15. The rotor core of claim 14, wherein the angle is between .+-.30
degrees.
16. The rotor core of claim 14, wherein the plurality of first
separation channels comprise a tapered region.
17. The rotor core of claim 16, further comprising a tapered port
connecting the plurality of separation channels to a flow path, the
tapered port being defined in the tapered region of the plurality
of separation channels.
18. A rotor assembly comprising: an outer housing; a first rotor
core removably disposable in the outer housing, the first rotor
core being rotatable in the outer housing about an axis of
rotation, the first rotor core having a rotor length defined along
the axis of rotation, the first rotor core having a plurality of
first separation channels having a first channel length that
extends along the axis of rotation less than the rotor length.
19. The rotor assembly of claim 18, wherein the first core
comprises a first end face and a second end face, the plurality of
first separation channels intersecting with only one of the first
and second end faces.
20. The rotor assembly of claim 18, further comprising: a second
rotor core removably disposable in the outer housing, the second
rotor core being rotatable in the outer housing about the axis of
rotation, the second rotor core having the rotor length, the second
rotor core having a plurality of second separation channels having
a second channel length that extends along the axis of rotation
less than the rotor length.
21. The rotor assembly of claim 20, wherein the first channel
length is different than the second channel length.
22. The rotor assembly of claim 20, wherein the plurality of first
separation channels have a first channel width and the plurality of
second separation channels have a second channel width, wherein the
first channel width is the same as or different from the second
channel width.
23. The rotor assembly of claim 18, wherein the outer housing
comprises a central portion and a pair of end caps, wherein at
least one end cap of the pair of end caps is selectively removable
from the central portion.
24. The rotor assembly of claim 23, wherein one end cap of the pair
of end caps is permanently connected to or integrally formed with
the central portion.
25. A method for achieving a linear scale separation of particles
of a product during centrifugation, comprising: selecting a first
rotor core and a second rotor core that have a common rotor length
and each have a plurality of channels with a channel length, the
channel length of at least one of the first and second cores being
less than the common rotor length, and the channel length of the
plurality of channels of the first rotor core being different than
the channel length of the plurality of channels of the second rotor
core; placing the first rotor core in a rotor housing to define a
first rotor assembly having a first volume capacity; rotating the
first rotor assembly about a rotation axis to achieve a first
particle separation of the first volume of the product; removing
the first rotor core from the rotor housing and placing the second
rotor core in the rotor housing to define a second rotor assembly
having a second volume capacity, the second volume capacity being
different than the first volume capacity; and rotating the second
rotor assembly about the rotation axis to achieve a second particle
separation of the second volume of the product which is a linear
with respect to the first particle separation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 62/338,563 filed on May 19, 2016, the entire
contents of which are incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present disclosure is related to centrifuge rotor cores.
More particularly, the present disclosure is related to centrifuge
rotor cores having partial channels.
2. Description of Related Art
[0003] In the biological and chemical sciences, there is often a
need to separate particulate matter suspended in a solution. In a
biological experiment, for example, the particles typically are
cells, subcellular organelles, viruses, virus like particles and
macromolecules, such as DNA fragments. A centrifugation process is
routinely used to perform the separation of these components from a
solution.
[0004] One common centrifugation technique is tube rotor
centrifugation, which employs a rotor that rotates or spins one or
more tubes containing the one or more desired analytes for
separation. While useful for separation of small volumes as may be
needed for laboratory use during product development, the use of
such tube rotor centrifugation techniques may not be considered to
be rapid enough and/or to be cost effective enough for certain uses
such as those common in a production environment. Thus, tube rotor
centrifugation techniques have generally not proven to be easily
scalable from the benchtop or lab environment to the production
environment.
[0005] Another common centrifugation technique is continuous flow
centrifugation, which employs a rotor and rotor core that rotates
or spins as the desired analyte or analytes flow continually over a
density gradient maintained within the rotor assembly. Such
continuous flow centrifugation techniques can include various
different process steps including, but not limited to static
gradient loading, static gradient unloading, loading of an unmixed
or discontinuous gradient, loading of a layered or step gradient,
dynamic gradient loading, dynamic gradient unloading, loading of
mixed or linear or continuous gradients, and any combinations
thereof.
[0006] As disclosed in U.S. Publication No. 2003/0114289A1, which
is incorporated herein in its entirety and is commonly owned by the
Applicant of the present disclosure, continuous flow centrifugation
can, in some instances, be configured for linear scalability, for
separations of different volumes or quantities, e.g., from
laboratory scale to pilot scale to industrial scale or from
industrial scale pilot scales to laboratory scale, using the same
or similar centrifugation systems. The method and apparatus allow
the same centrifuge systems can be used for sedimentation processes
of multiple scales while maintaining substantially the same
separation characteristics for each process by, at least in part,
interchanging different sized and configured rotor cores within the
rotor housing.
[0007] It has been determined by the present disclosure that the
rotor cores disclosed herein, which include a partial channel,
provide enhancements and improvements to the prior art scalable
continuous flow centrifugation.
SUMMARY
[0008] A rotor core is provided that has a plurality of partial
channels, namely channels that extend less than an entire length of
the rotor core.
[0009] A rotor assembly is provided that has an outer housing with
a removable rotor core disposed therein. The rotor core has a
plurality of partial channels, namely channels that extend less
than an entire length of the rotor core.
[0010] A method for achieving a linear scale separation of
particles of a product during centrifugation is provided. The
method includes operating a centrifuge apparatus at certain
predetermined parameters depending upon a product to be separated;
placing a first rotor core in a rotor housing to define a first
rotor assembly having a first volume capacity; rotating the first
rotor assembly in the centrifuge apparatus and so as to achieve a
first particle separation of the product; removing the first rotor
core from the rotor housing and placing a second rotor core in the
rotor housing to define a second rotor assembly having a second
volume capacity; and rotating the second rotor assembly in the
centrifuge apparatus so as to achieve a second particle separation
of the product which is a linear scale with respect to the first
particle separation. The first and second rotor cores have a common
rotor length and each have a plurality of channels with a channel
length. The channel length of at least one of the first and second
cores being less than the common rotor length. Additionally, the
channel length of the plurality of channels of the first rotor core
is different than the channel length of the plurality of channels
of the second rotor core.
[0011] The above-described and other features and advantages of the
present disclosure will be appreciated and understood by those
skilled in the art from the following detailed description,
drawings, and appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 is a front elevational view of a centrifuge apparatus
according to the present disclosure;
[0013] FIG. 2 is a sectional view of an exemplary embodiment of a
rotor assembly according to the present disclosure;
[0014] FIG. 3 is a top perspective view of an exemplary embodiment
of a rotor core according to the present disclosure;
[0015] FIG. 4 is a partially exploded view of the rotor core
according of FIG. 3;
[0016] FIG. 5 is a schematic view of a first exemplary embodiment
of a flow path through the rotor core of FIG. 3;
[0017] FIG. 6 is a schematic view of an alternate exemplary
embodiment of a flow path through the rotor core of FIG. 3;
[0018] FIG. 7 is a top perspective view of an alternate exemplary
embodiment of a rotor core according to the present disclosure;
[0019] FIG. 8 is a view of the rotor core of FIG. 7 illustrating
flow channels;
[0020] FIG. 9 is a side view of the rotor core of FIG. 7;
[0021] FIG. 10 is a sectional view of the rotor core of FIG. 7;
[0022] FIG. 11 is a top perspective view of another alternate
exemplary embodiment of a rotor core according to the present
disclosure;
[0023] FIG. 12 is a view of the rotor core of FIG. 11 illustrating
flow channels;
[0024] FIG. 13 is a side view of the rotor core of FIG. 11;
[0025] FIG. 14 is a sectional view of the rotor core of FIG.
11;
[0026] FIG. 15 is a top perspective view of a prior art rotor core
used to compare to the rotor core of FIG. 11;
[0027] FIG. 16 is a graph comparing the performance of the rotor
core as in FIG. 11 and FIG. 15;
[0028] FIG. 17 is a bottom perspective view of yet another
alternate exemplary embodiment of a rotor core according to the
present disclosure;
[0029] FIG. 18 is a top perspective view of the rotor core of FIG.
17; and
[0030] FIG. 19 is a view of the rotor core of FIG. 17 illustrating
flow channels.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring to the drawings and in particular with
simultaneous reference to FIGS. 1-4, a centrifuge apparatus 10
according to the present disclosure is shown in use with an
exemplary embodiment of rotor core 12 having a plurality of
separation channels 14 defined therein.
[0032] Advantageously, rotor core 12 allows centrifuge apparatus 10
to be utilized in a process for separating components of a product
sample in which the volume of the product sample can be scaled up
or down while maintaining substantially the same selected
separation parameters of the process or to enable one centrifuge to
be used for multiple scale processes that do not necessarily need
to be scaleable but should have a similar functioning process.
[0033] According to the present disclosure rotor core 12 has
channels 14 with a channel length (C.sub.Lthat extends less than an
overall length of the rotor core, referred to herein as a rotor
length (R.sub.L). Thus, rotor cores 12 of the present disclosure
are referred to as having "partial channels", namely having
channels 14 that extends less than the entire length of the rotor
core. In some embodiments, channel length (C.sub.L) is between 5%
and 90% of rotor length (R.sub.L), preferably between 20% and 80%,
with between 25% and 75% being most preferred, and any subranges
between these ranges.
[0034] Exchanging a rotor core 12 having channels 14 of a first
partial channel length (C.sub.L) in centrifuge assembly 10 with a
rotor core 12 having channels 14 of a second channel length
(C.sub.L)--where the second channel length is longer or shorter
than the first--allows different volumes of analyte or analytes to
be processed in a linearly scaled essentially similar manner.
[0035] Rotor core 12 has channels 14 with a channel width
(C.sub.W)--where the channel width (C.sub.W) and channel length
(C.sub.L), as well as the number of channels, define the volume of
the rotor core. Since the present disclosure provides rotor cores
12 having partial channels 14, the channel width (C.sub.W) is
increased to provide the same volume as rotor cores having longer
channels. Stated another way, by providing rotor cores 12 having
channels 14 of partial or limited channel length (CO, the rotor
cores having increased or wider channel widths (C.sub.W). As used
herein, the channel width (C.sub.W) is defined as a measurement of
arc length of channel 14 at the outer diameter of rotor core
12.
[0036] Without wishing to be bound by any particular theory, it is
believed that rotor cores 12 of the present disclosure--that have
partial channels 14--provide increased stability of the separation
gradient during rotation by centrifuge apparatus 10. Simply stated,
partial channels 14 of the present disclosure are shorter than the
channels of the prior art and assuming a common channel volume,
result in wider channels than those of the prior art. It is
believed that the short, wide partial channels 14 of the present
disclosure provide increased stability of the separation gradient
during rotation by centrifuge apparatus 10.
[0037] It is also believed that increased gradient stability
provides an environment where the density gradient `profile` can be
retained for a substantially longer period of time and therefore
allow for a process to be conducted where the analyte or analytes
can be successfully collected and the gradient remain in an
essentially similar profile as compared to each other. This means
that the analyte or analytes accumulation and resolution of
impurities remains essentially the same for either scale of
operation hence they are of a linear scale.
[0038] In some embodiments, rotor core 12 has an aspect ratio of
channel width (C.sub.W) to channel length (C.sub.L) from 10:1 to
1:10, preferably 1:1 to 1:10, more preferably from 1:1 to 1:5, with
1:1 to 1:3 being most preferred, and any subranges there
between.
[0039] Centrifuge 10 includes a tank assembly within which is
housed a drive motor 16 and a rotor assembly 18. Drive motor 16 is
used to spin rotor assembly 18 at speeds sufficient for separation
of the desired analyte or analytes.
[0040] Rotor assembly 18 includes an outer rotor housing 20 with
removable rotor core 12 positioned therein. Housing 20 includes a
central portion 22 and a pair of end caps 24, 26. At least one of
end caps 24, 26 is selectively removable from central portion 22 so
as to allow rotor core 12 to be inserted or removed from housing
20. In some embodiments, one of end caps 24, 26 can be permanently
connected to or integrally formed with the central portion 22.
[0041] In some embodiments, centrifuge apparatus 10 can include a
lift assembly 28 to raise one or more of drive motor 16 and the
rotor assembly 18. Additionally, centrifuge apparatus 10 can
include a console assembly 30, which is in communication with drive
motor 16 and, when present, lift assembly 28 to control the
respective functions thereof.
[0042] In this manner, rotor cores 12 having channels 14 of
differing channel lengths (C.sub.L) can be received in rotor
assembly 18 and the rotor assembly can be installed in the
centrifuge apparatus 10 to process--preferably in a linearly
scalable manner--differing volumes of analyte or analytes.
[0043] In some embodiments, rotor assembly 18 includes an insert 32
at a first face 34 and/or a second face 36 of rotor core 12. In the
illustrated embodiment, insert 32 is removable in a bore 38 of
rotor core 12 located by a pair of pins 40, a spring 42, and a seal
or 0-ring 44. Spring 42 normally biases insert 32 upwards along
pins 40 away from faces 34, 36. In this manner, insert 32 can
assist in seating rotor core 12 in housing 20 and end caps 24, 26
in a desired manner.
[0044] While rotor core 12 is illustrated in FIG. 2 having insert
32 at both faces 34, 36, it is contemplated by the present
disclosure for the rotor core to have at least one of the inserts
integrally formed therewith as illustrated in FIGS. 5-6. Without
wishing to be bound by any particular theory, it is believed by the
present disclosure that rotor core 12 having integral insert 32 at
least at one of faces 34, 36, improved flow through rotor assembly
18 by eliminating a region of reduced flow (i.e., dead leg) that
can form around the insert. Although not illustrated, it is
contemplated by the present disclosure for both inserts 32 to be
integral to rotor core 12.
[0045] A first exemplary embodiment of the flow path through rotor
core 12 of FIG. 3 is illustrated in FIG. 5, and an alternate,
opposite flow path through the rotor core is illustrated in FIG.
6.
[0046] Rotor core 12 of FIGS. 3-4 and 5-6 includes a flow path
defined by an axial channel 44, a plurality of radial channels 46,
the plurality of separation channels 14, a plurality of face
channels 48, and, when insert 32 is present, a plurality of insert
channels 50. Preferably, the number of separation channels 14 is
common with the number of radial and face channels 46, 48. Of
course, it is contemplated by the present disclosure for core 12 to
not include insert 32 and here, the core includes any desired
number of face channels 48 such as six or less channels, more
preferably four channels.
[0047] As shown in FIG. 5, centrifuge apparatus 10 can be operated
so that the flow of analyte or analytes through the flow path
enters rotor core 12 at insert 32 proximate face 36, passes axially
through the rotor core via axial channel 44, passes radially
through the rotor core via radial channels 46, and enters
separation channels 14. After passing through separation channels
14, which include a density gradient, any unseparated analyte or
analytes and/or flow through passes over face 34 via face channels
48, then over insert 32 via insert channels 50 before exiting rotor
assembly 18.
[0048] Preferably, core 12 includes a port or opening 52 connecting
radial channels 46 and separation channels 14 that includes a taper
such that the port is wider at an interface with separation
channels 14. Without wishing to be bound by any particular theory,
the taper of port 52, when the flow path is as illustrated in FIG.
5, spreads the particles in the analyte or analytes across a
greater area of the separation gradient, which can mitigate the
impact of the particles on the gradient and maintain the separation
performance (e.g., stability) of the gradient. Simply, it is
believed that the momentum of the analyte or analytes and/or flow
through traveling radially outward can physically disrupt or cut
through the gradient in separation channels 14. The taper of port
52 is believed to lessen this effect by spreading the momentum
across a larger area of the gradient.
[0049] It should be recognized that radial channels 46 are
illustrated as being perpendicular to an axis of rotation (A) of
rotor core 12. Of course, it is contemplated by the present
disclosure for radial channels 46 to be angled with respect to a
normal line (N) through the axis (A). For example, it is
contemplated by the present disclosure for radial channels 46 to
angled with respect to the normal line (A) by between .+-.30
degrees, more preferably between .+-.10 degrees, with .+-.5 degrees
being most preferred, and any subranges there between.
[0050] Again without wishing to be bound by any particular theory,
it is believed by the angle of radial channels 46 can be used to
slow or reduce the momentum with which the analyte or analytes
and/or flow through impacts the gradient in separation channels 14.
For example, the momentum flow through radial channels 46 of FIG. 5
can be slowed by providing the radial channels with a downward
angle with respect to normal line (A).
[0051] Conversely and as shown in FIG. 6, centrifuge apparatus 10
can be operated so that the flow of analyte through the flow path
enters rotor core 12 at insert 32 proximate face 34. Here the flow
passes or analytes over insert 32 via insert channels 50, passes
over face 34 via face channels 48, where the flow enters separation
channels 14. After passing through separation channels 14, which
include a centrifugation gradient, any unseparated analyte or
analytes and/or flow through passes enters rotor core 12 via radial
channels 46, flows into radial channel 44, and exits rotor core 12
at insert 32 at face 36.
[0052] Referring now to FIGS. 7 through 10, another alternate
embodiment of rotor core 112 is shown. Here, rotor core 112 has the
same geometry and dimensions including rotor length (R.sub.L) and
channel width (C.sub.W) as rotor core 12 shown in FIGS. 3 through
6. However, rotor core 112 has partial channels 114 with have a
channel length (C.sub.L) that results in a volume of rotor core 112
that is 100 ml.
[0053] Accordingly, it can be seen that use of rotor assembly 18 in
centrifuge assembly 10 can be easily scaled, in a linear manner, by
starting with the rotor core 12 of FIGS. 3 through 6 that has a
volume of 50 ml, then using the rotor core 112 of FIGS. 7 through
10 that has a volume of 100 ml.
[0054] It should be recognized the present disclosure is
illustrated above with respect to rotor cores 12 and 112, which
have three separation channels 14, 114. Of course, it is
contemplated by the present disclosure for rotor cores having any
desired number of separation channels.
[0055] For example, and referring to FIGS. 11 through 14, another
alternate embodiment of rotor core 212 is shown. Here, rotor core
212 includes six partial channels 214 with have a channel length
(C.sub.L) that is 25% of rotor length (R.sub.L). Further, it is
contemplated by the present disclosure for rotor core 212 to have
any desired channel length (C.sub.L) that less than rotor length
(R.sub.L).
[0056] Rotor core 212 of FIGS. 11 through 14 has partial channels
214 and can be compared to the prior art rotor core 212' shown in
FIG. 15. Rotor core 212' is commercially available from the
Applicant under the tradename PK3-400.
[0057] For ease of comparison, rotor core 212 and rotor core 212'
have a common rotor volume of 400 ml. Here, rotor core 212 has
partial channels 214 with channel length (C.sub.L) that is less
than the rotor length (R.sub.L). By contrast, while the prior art
rotor core 212' has channels 214' with a channel length (C.sub.L)
that is equal to the rotor length (R.sub.L)--namely lacks the
partial channels of the present disclosure. As a result, channels
212 have a channel width (C.sub.W) that is substantially wider than
the channel width (C.sub.W) of rotor core 212' but have the same
volume.
[0058] FIG. 16 is a graph comparing the performance of rotor core
212 to the performance of the prior art rotor core 212'. During the
comparison test, rotor core 212 was configured with the flow
direction illustrated in FIG. 5. The standardized parameters for
both tests include use of a commercially available PKII
ultracentrifuge, a rotor speed of 35,000 rpm, a separation gradient
that includes 200 ml load volume of 55% w/w sucrose solution and
200 ml load volume of water.
[0059] As can be seen from FIG. 16, the gradient collected from
both tests illustrate a collection that is considered, for the
purposes of the present application, linear with respect to one
another. Thus, the results of the comparison in FIG. 16 illustrate
linearity between the separation using the prior art rotor core
212' that has full length channels 214' and rotor core 212 that has
the shorter, wider partial channels 214 according to the present
disclosure.
[0060] More features of the partial channel rotor cores of the
present disclosure are disclosed with respect to FIGS. 17 through
19. Rotor core 314 illustrates an example of radial channels 346
that are angled--by a positive angle--with respect to a normal line
(A).
[0061] Rotor core 314 includes a tapered region 354 within channels
314. Tapered region 354 can be used to provide further scalability
to the volume of rotor core 314.
[0062] In some embodiments, axial channels 346 have ports 352 at
the interface with separation channels 314 that terminate in the
tapered region. Additionally and without wishing to be bound by any
particular theory, termination of ports 352 in tapered region 354
is believed to reduce or mitigate effects of momentum of the
analyte or analytes and/or flow through on the gradient in channels
314.
[0063] It should also be noted that the terms "first", "second",
"third", "upper", "lower", and the like may be used herein to
modify various elements. These modifiers do not imply a spatial,
sequential, or hierarchical order to the modified elements unless
specifically stated.
[0064] While the present disclosure has been described with
reference to one or more exemplary embodiments, it will be
understood by those skilled in the art that various changes may be
made and equivalents may be substituted for elements thereof
without departing from the scope of the present disclosure. In
addition, many modifications may be made to adapt a particular
situation or material to the teachings of the disclosure without
departing from the scope thereof. Therefore, it is intended that
the present disclosure not be limited to the particular
embodiment(s) disclosed as the best mode contemplated, but that the
disclosure will include all embodiments falling within the scope of
the appended claims.
* * * * *